He put a dent in Munster's title ambitions last January when he scored a try in Leicester's 13-6 win at Thomond Park.
But with Leicester failing to make an impression in this season's Heineken Cup, the Kildare man is weighing in behind Munster as he feels they can get the better of Saracens in Sunday's mouth-watering semi-final clash at the Ricoh Arena.
"I think Saracens are a good side. It will be on a football field again, Saracens are used to playing on that hard, fast surface.
"If Munster take Saracens lightly as the Ospreys did (in the quarter-finals), then they could be in trouble. But I don't see Munster not having done their homework and not being prepared well enough for this game," Murphy said.
"It's a Heineken Cup semi-final, I'm sure they will have done a lot of work. I see Munster winning it reasonably well.
"I think Saracens will try and keep it quite tight, try to nick the win, maybe a one-try victory and try to defend very well. But I don't think there are many teams better than Munster when it comes to a tight game."
Murphy knows the Saracens squad well having played against the London club regularly in the Guinness Premiership and he picked out some of their players to watch out for on Sunday.
"I think they've got some good forwards. Chris Jack being out is a huge loss for them. They have, in Cencus Johnston, probably one of the best ball-carrying forwards around.
"A big Samoan prop, he's a threat when he's fresh. He really needs to be made work very, very hard at scrum and lineout time so he doesn't have that energy to run around and carry the ball.
"They've got some good players in the backs too. I suppose a key in any big game is that if you don't at least get parity up front, it makes it very, very difficult for the backs," he added.
(Their half-backs) (Neil) de Kock and (Glen) Jackson are good players. I don't think Jackson has been playing well this year as he was last year. Still, in a big semi-final he can definitely raise his game.
"Saracens have got some good players, a lot of experience. They're a good side. I don't think anyone should take them lightly but I think Munster have the beating of them."
Click here to read Geordan Murphy's thoughts on his international future and the appointment of the new Ireland coach.